# NTSB SEA91LA066: Hughes 369D, N1088L, Roseburg, OR, March 11, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 11, 1991, 14:15 local (22:15 UTC)
- Place: Roseburg, OR
- Coordinates: 43.250568, -123.239746 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.2506&lon=-123.2397&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report May 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41399
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA066
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41399/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA066

## Probable cause

A LOSS OF ENGINE POWER FOR UNDETERMINED REASONS.  A FACTOR RELATED TO THE ACCIDENT WAS: THE LACK OF A SUITABLE AREA FOR AN EMERGENCY LANDING.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power, cruise
  - reason for occurrence undetermined (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - none suitable (contributing factor)

## Analysis

THE PILOT REPORTED THAT THE HUGHES 369D WAS CRUISING BETWEEN 300 AND 500 FEET ABOVE THE SURFACE, WHEN HE HEARD A LOUD 'POP' AND THE ENGINE SPOOLED DOWN RAPIDLY.  HE STATED THAT HE HAD NO PREVIOUS INDICATION OF A PROBLEM UNTIL THE ENGINE ABRUPTLY LOST POWER.  HE INITIATED AN AUTOROTATION AND LANDED ON A SLOPED PORTION OF THE HIGHWAY.  AFTER TOUCHDOWN, THE RIGHT SKID DROPPED APPROXIMATELY 20 INCHES AND THE MAIN ROTOR BLADES STRUCK THE TAILBOOM.  NO PREIMPACT MECHANICAL DISCREPANCY WAS FOUND.

## Aircraft

- Registration: N1088L (not matched to a registry record)
- Reported make and model: HUGHES 369D
- Category: Helicopter
- Serial number: 300678D
- Engines: ALLISON 250-C20B 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Gregory Forest Products
- Registered owner: Gregory Forest Products
- Departed: S21, SUNRIVER, OR
- Destination: GLENDALE, OR
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; toxicology performed; flight hours: 10,023 total, 4,950 in this make and model, 9,760 as pilot in command, 116 in the last 90 days, 45 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 6 statute miles
- Lowest ceiling: 1,500 ft overcast
- Temperature: 34 °F, dew point -0 °F
- Altimeter: 30.00 inHg

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19910311005219A](https://openairdocs.org/incident/19910311005219A), Mar 11, 1991: Hughes 369D, Roseburg, OR, Substantial damage. Reported loud bang. Autorotated to slanting highway pavement. Hit one skid,dropped to other. Chopped tail boom.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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